Electric furnace



J. J. FRANK Nov, 19, 1929.

ELECTRIC FURNACE Filed Dec. 21, 1927 Il IIII,l

1 otonto(1 Nov. 19, 1929 PATENT oFFcE 1 Ho tion 1ed Decen1ber 31, 1937. seri81 1, 241,682-

M i11ventio1 rolotos to oleotrio furnoceS ond os foI' its obiect tho proviSion of on iIn Pfoved orraJ1gen1ent of oondootofs vvhereby the feootonoo of tho fufnooe eleotrio oifouit iS rednced.

y invontion 11oS esI)eoiol o p1icotion to furnooes eII1 )1oying oolnp8rtive y lorge cI11'- fents of the nlognitudo, for exoInplo, of ten to tvve1ty thousand oII1 )eres, Suoh oS ore uSed in electric sIIlelting furnaces. vvith such lorge curfelfts the feaotance of tho fornooe cirouit hos 811 in1poftont eeot on tho o erotion of the generoting eqnipnlent, the least osSiblo feaotonce belng deSirablo in ordef thot tho furnoce load Wi11 hove the 111oSt fovofoble povver footof.

In oorrying out Iy invention I en1Ploy o speoia1 orrongeInont of bus bors leodlng to the furnooe terIninolS, tho electricol oonnection vvith the terninal Inost relnote vvith respect to the Su )1 Source being oected by IIleons of o plura ty of condnotofs or buS bors eleotfically connected in Porone1 ond or fonged in oloSe Proxin1ity to tho furnoce struoture on voriouS sideS thereof.

or n1ore con1 lete understanding of Iny invention reference Shonld be had to the ooconponying drovving the Single agure of Whioh is 8 Inoro 01' leSS dio aJI1IIlatic side elev8tion vieW artly in sect1on of an electrode furnoce eInbodying Iny invention.

1feferring to tho drovving, I hove Shovvn n1y invontion in one forIn os o 1ied to o fu1' nace of the electrode ty e 8 though it WiH be understood that nny lnvention is opplioob1o to various other typeS of furnaces, Such os those em loying o heoting fesistor e1e 11ent, in vvhch it is deSiroblo to reduce the feootanoe of the furnoco cirouito The furnoce coII1 )riSes 8n elongoted cruoible 10 Inodo of suitoblo heot fefrootory n1terio1 forn1ing ol feceptao1e for the Inolten 1notoll 11. 1xtend ing through tho vvo11S of the receptoolo of pointS above the lovel of tho nleto1 ond of op I)osito ondS of the reoeptocle oro tvvo olootfodoS 12 ond 13. TheSe eleoffodos ofo iI1- olined dovvnvvafd tovvord tho interiof of tho fecePtado ond are orronged to bo in ofcing rolotion vvith the ohofge, of they II1oy bo in orcing rolotion vvith eoch othor. The l1olten oharge oon be WithdroWn from the botton1 of the receptaole through o tP oPonin 14. 1 heat inSuloting oover 15 is I)fefefo1y pro vided for tho orucible,

I1eotIio current iS Su lied to the electrodes ffon1 o suitable olternoting ourfent Snpp1y source of lovv vo1toge, suoh os the seoondofy of the tronsforIne1' 16, the electricol oonnec tions being Inode thTough buS bors 17 ond 18 vvhich are of lorge cross seotiono1 ofeo in ofder thot they Inol cafry the relatively 1orge ourrentS require vvhich Inoy be os high os 20,000 oInperes oI' n1ore, depending of courSe n on the oopooity of the furnace. The bus br 18 is 1ed directly to the neofef electrodo 13, i. o., the electrode vvhioh is nearer the transforIner 16 or othervvise Inore easily ocoeSsiblo for the eleCtrical connections. It WiH be undefstood that vvith the re1otively heovy ourrents involved the electrical connections are Inode os Short os PosSible in ordeT to keop both the reSiStanoe and the inductonce of tho oirouit at 8 IniniInum volue.

FoI the purpoSe of reduoing the reactance of the cil'cuit, Inore partioularly the in ductance of the circuit, the bus bor 17 iS conneoted to the Inore ren1ote eleCtrode 12 through a plurolity of bUS barS 19, 20, 21 ond 22 eleotricoll connected in oralle1, vvhich extend lengthvviSe in C10Se rOXiInity vvith the to bottoIn and op osite sides of the furnace reSpeotively. The buS bar 17 is electricony connected to theSe bus barS throu h on inter- Inediate conneCting bus bar 23 W ich is con neCted to the endS of the busbors 19 to 22 inoluSive. The op )osite ends of theSe bus borS ore electrioally conneoted to the ele( trode 12. The buS borS 1922 inolusive aro of felatively SInall croSS Sectionol oreo oS oon pored vvith the buS bor 17, their combined our- Tent oarr ing CaI)acity being e I1a1 to that of the bus bar 17. I referably, ovvever, they ofo of felatively gfeat Tvidth vitf1 fespect to the to bottoIn and SideS of the crncible vvith correSPondingly rednced thickneSS.

I have found that this diStribution of the conduotorS or buS barS vvith reSpect to the furuooe v7allS very greatly red11ces the fe octance of the furnace ciI'cI1it coIn ared vvith the reactonCe vvith the uSualoonnections in vvhich the bUS bar 17 Tvould be extended and conneCted directly to the eleotrode 12. In fact, the reactance vith the arTongeInent shovvn IT1ay be only fractional part of the roaotanCe vvifh the uSual o rangenlent.

Since the buS baT 19 extends oveI the top of the fuTnace, it vvin be eoeSsofy to feInove the cover 15 by IIoving it sidevviSe ofter it hos been lifted someWhot, ny Snitoble of rongenent can be uSed in order to fovide fol oharging the furnaoe, The blls bor 19 Inoy bo oInitted entirely, foI exaIn le, in vVhich caSe onl three ouXi1iry buS bars vvonld be rovide and the reactanCo of the circuit Woold stin be foHnd to be great1 rednCed.

vVhile I have deScribed lny lnvention aS enbodied in concrete forIn and os operating in SpeciHc nlanner in aCcordance With the rovisionS of the atent S tatI1teS, it should be understood that I (lo not lin1it IIly invention thereto since variouS InodiHcationS thoreof vvill Suggest then1SelveS to thoSe Skilled in the ort vvithout de orting from the Spirit of my invention, the SCo )e of Which iS Set forth in the annexed clain1S- vvhat I Clain1 aS now and (fesire to seCnre by IJotterS I atent of the Inited StoteS, iS=

1. The combination With an electric furnoce, of electriCol connectionS for single terInina1 of Sai(1 furnaceooInpriSing H h1- rlity of conductorS diStributed along o 1)ll1- Tality of the vvallS of Soid fnrnace in cloSe ProXin1ity thefeto.`

2. 1he coInbination vith an eleCtric furnace, of connectionS therefor coInpriSing o buS bor oonnected directly to one eleotrode and a plurality of buS borS oonneoted to the otheI' electrode, Soid Plurality of buS bo1'S being rronge(1 1engthviSe in oloSe Proxi- Inity to o plurality of the 1lS of Said furnce.

3. The coInbination T,ith an electrio fur noce, of connectionS therefor ConpriSing a, 1urlity of bus barS, e]eCtricl connectionS otvveen one of Said buS brS End the Inore eSi1 acoeSSible electrode and e1ectriC1 con neotions betvveen the other buS bar and the n1ore reInote electrode, colT1 riSing a plurglity of buS barS of relotively SInall croSS Section eX- tending lengthWiSe in close proxin1ify to o Plurality of the vvollS of Said furnoce So aS to rednCe the inductance of the circ11it for soid furnooe.

4. The con1binotion vvith an electrio furnooo, of on electrio supPly cirouit therefor incl11(1ing on e1ectfic1 Sup ly sourco and lurolity of electricol conductors leoding ron1 at least one terIninal of Said Suppl Souroo to o11e terInina1 of said furnace, Soi

oonductors being diStfibllted in close Proxi- Inity to od lurolity of the top, bottoIn ond Side vvallS of Soid furnace So os to Teduce the inductonce of soid oircuit,

In vvitneSS vvheTeof, I have hefeunto set Iny hand thiS 19th day of Dec., 1927. 

